So I screwed up I was taking out the lifters on my 350 it's on an engine stand and one of the o rings on the lifters fell in the hole where the distributor go I know this is a big problem but will it be easy to find once I pull out the cam and pistons??????

 

Yeah, you'll find it. Probably just fell to the bottom of the pan. Even if you flip the engine over and it drops onto the rotating assembly you will still find it easily. There aren't that many places for something that big to hide.

I once took apart and engine and found a small screwdriver laying in the lifter valley!